The proposed research will examine mechanisms underlying links between psychosocial stress and health outcomes as individual's age. Tapping into an existing longitudinal dataset, the propose research will test whether, when, and how exposure to different types of stress early in life statistically interact with life stress in adulthood to predict negative health outcomes. We predict that individuals exposed to higher levels of physical and/or social stress early in life will: (a) be more stress-reactive in response to difficult/challenging situations in adulthood (i.e., hyper HPA-axis reactivity, indexed by daily and event- elicited cortisol levels), (b) have greater inflammation (indexed by levels of C-reactive protein/interleukin-6), and (c) report more health problems in adulthood. These outcomes should be most pronounced when vulnerable individuals (those who experienced more stress early in life) encounter higher levels of stress in adulthood, with greater early life stress statistically interacting with greater current life stress to forecast more negative cortisol, inflammation, and health outcomes. We will also test whether and how the quality of caregiving and social support earlier in life moderates (strengthens or weakens) relations between early life stress and adult health outcomes. The results should facilitate the development of interventions designed to prevent vulnerable individuals from experiencing negative health outcomes in adulthood.